IV. 
DICT Y OTA CE-ZE. — Hydroclathrus. 
119 
SPECIES OE DOUBTFUL AFFINITY. 
3. Asperococcus intricatus, J. Ag., “ frond tubular, branched, sub-hemi spheri- 
cally expanded, subrepent ; branches intricate, gradually attenuated, decompound- 
dichotomous ; the apices forked.” J. Ag. Sp. Alg. vol. 1, p. 77. 
Hab. Tropical. At Yera Cruz, Mexico. ( Liebman ). 
I am not acquainted with this plant, which scarcely seems to fall naturally 
under this genus. 
XI. HYDROCLATHRUS, Bory. 
Frond membranaceous, convex, hemispherical, bag-shaped, regularly pierced with 
orbicular holes, which gradually dilate more and more, until the plant becomes a 
clathrate net, eventually mishapen and ruptured. Margin of the apertures involute. 
“ Spores minute, globose, collected into clot-like, scattered, innate sori, accompanied 
by club-shaped, jointed filaments.” {Mont.) 
This is a very remarkable plant, and of so peculiar a habit, as well as distinct struc- 
ture, that I can hardly imagine any person who has had an opportunity of seeing 
it alive on its native rocks, placing it in the same genus with Asperococcus sinuosus ; 
although my valued friend Prof. J. Agardh even doubts its specific diversity from 
that species. I must suppose that Prof. Agardh has formed his judgment from an 
examination of dried specimens, which are so wholly unlike the living plant in 
appearance, and can be so imperfectly examined when remoistened, that a satisfac- 
tory opinion can scarcely be formed from them. I regret that the microscope 
which I had with me at Key West was not of sufficient power to enable me to 
make out the anatomical structure perfectly, and the plant decomposed so 
rapidly that it was difficult to obtain good slices of the membrane sufficiently 
thin for examination. When fresh from the sea, the frond was quite crisp, and 
could readily have been cut, but my specimens (collected at Sand Key) had to be 
brought a long way in an open boat, under a hot sun ; and although every care was 
taken to keep them cool, and though they were brought in buckets of water, decom- 
position had commenced long before they reached Key West, and then, in the 
attempt to save from destruction a large gathering of other Algae, the fruit of the 
same excursion, only very imperfect notes could be made on the present curious 
plant. Such sections as I was able to make through the membrane showed me that 
it was composed of several rows of cells ; the inner rows, occupying almost the 
whole thickness, being formed of large, colourless cells, filled with fluid, distended, 
